Answer:
a) The percentage of athletes whose GPA more than 1.665 is 87.49%.
b) John's GPA is 3.645.
Step-by-step explanation:
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

a)Find the percentage of athletes whose GPA more than 1.665.
This is 1 subtracted by the pvalue of Z when X = 1.665. So



has a pvalue of 0.1251
1 - 0.1251 = 0.8749
The percentage of athletes whose GPA more than 1.665 is 87.49%.
b) John's GPA is more than 85.31 percent of the athletes in the study. Compute his GPA.
His GPA is X when Z has a pvalue of 0.8531. So it is X when Z = 1.05.




John's GPA is 3.645.
The answer is 1/2 in fraction form because 0.5 is half of 1
Probably you are supposed to compute

Factorize the numerator and denominator, then simplify:
14. 36x^2 - 16
4(9x^2 - 4) =
4(3x + 2)(3x - 2) <==
15. 3x^2 + 10x - 8
(3x - 2)(x + 4) <==
16. 5x^2 - 16x + 15 = 4x - 5
5x^2 - 16x - 4x + 15 + 5 = 0
5x^2 - 20x + 20 = 0
5(x^2 - 4x + 4)
5(x - 2)(x - 2)
x - 2 = 0....x = 2
3m² = 3 - 8m
0 = 3m² + 8m - 3
0 = (3m - 1 )(m + 3)
m = -3, 0.33